Amachree,

I have seen u-bolts used as anchors in many systems (in one absurd case, the engineer used two u-bolts on a 16” line with 7000 lb of axial load); I have seen several situations in which the “anchor” failed; and I have seen various formulae for calculating u-bolt restraint forces, all of which I think are dubious. In addition, I’ve worked with many clients who do not permit u-bolts at all, in part because of their doubtful restraint capabilities and various other reasons (nuts fall off; nuts not replaced after a turnaround; u-bolts intended to be double-nutted with a gap are tightened down hard; etc.). Personally, I prefer not to use them. In practice, however, they should at least be limited to small lines, used only where low forces are expected, and never used as the primary piping support.

Regards.